62 PRACTICAL ORGANIC CHEMISTRY
It must be remembered that ether is highly inflammable, and
also exceedingly volatile, and great care should be taken that
no flame is in the neighbourhood of the liquid. It must on no
account be distilled over the bare flame, but always from the
water-bath, and then with a long well-cooled condenser. The
distillation of large quantities should be avoided as far as
possible. In such cases it is convenient to employ a distilling
flask of moderate size (250 c.c.), and to add, as the liquid distils,
a fresh supply of ether or ethereal liquid from a tap-funnel
inserted through the neck of the flask, which can be done
without interrupting the distillation.
Bthylene Bromide. CH2Br. CH2Br.
Balard, Ann. Chim. Phys. 1826 (2), 32, 375 ; Erlenmeyer.
Bunte, Annalen, 1873, 168, 64.
25 grms. (30 c.c.) absolute alcohol.
150 „ (So c.c.) cone, sulphuric acid.
200 „ (65 c.c.) bromine (which must be measured
out in the fume-cupboard).
300 „ of a mixture of 100 grms. (124 c.c.) alcohol
and 200 grms. (108 c.c.) cone, sulphuric
Fit up an apparatus as shown in Fig. 50. It consists of a
round flask (2 litres), which is furnished with a double-bored
cork. A tap-funnel is inserted through one hole and a delivery
tube through the other, by which it is connected with two
wash-bottles with safety tubes. A useful form of wash-bottle is
that shown'in Fig. 50 and in section at a. Otherwise a three-
necked Woulff bottle will serve, with a long tube inserted through
the central neck. The wash-bottles are one-third filled with
caustic soda solution. The two ordinary wash-bottles standing
in the trough of water contain the bromine. The first contains
about 50 c.c. of bromine and i c.c. of water and the second about
15 c.c. of bromine and i c.c. of water. The latter is attached to
a wide U tube or cylinder containing pieces of soda-lime. If a
cylinder is used a layer of glass fragments or marbles should